KR20010098759A - Hybrid lens and method for forming the same - Google Patents

Abstract

In the method of forming a composite lens which transfers an aspherical composite layer made of an ultraviolet curable resin cured by irradiation of ultraviolet rays using at least one surface of a convex lens by a molding die, the molding die is formed by using a material through which ultraviolet rays are transmitted. The aspherical composite layer is characterized in that it is transferred to a convex lens by irradiating ultraviolet rays from the molding die side and curing the ultraviolet curable resin with ultraviolet rays transmitted through the molding die.

Description

Compound lens and molding method of compound lens {HYBRID LENS AND METHOD FOR FORMING THE SAME}

The present invention relates to a composite lens and a molding method of the composite lens, wherein the aspherical composite layer is formed of an ultraviolet curable resin. In particular, the present invention uses an ultraviolet ray transmitted to a molding die for molding an aspherical composite layer, and irradiates the resin with ultraviolet rays from the molding die side to cure the resin, thereby avoiding the influence of the curved surface of the lens and the like. It was made to be molded.

Background Art Conventionally, so-called composite lenses, in which an aspherical composite layer is formed on a single lens made of optical glass as a base material, have been put into practical use as a means for forming aspherical lenses relatively inexpensively. This composite lens is produced by transferring an aspherical composite layer made of ultraviolet curable resin to the lens surface of a single lens made of optical glass.

FIG. 13 shows a conventional molding method for a composite lens, in which a predetermined amount of ultraviolet curable resin 32 is dropped on a transfer surface 31 for forming an aspherical composite layer on a mirror surface of a mold 30. Thereafter, the convex lens 33 is set in the mold 30 and the convex lens 33 is fixed to the mold 30 by using the support frame 34 so that the ultraviolet curable resin 32 can transfer the entire transfer surface 31. Fill it up. In this state, the ultraviolet curable resin 32 is cured by ultraviolet rays transmitted through the convex lens 33 by irradiating ultraviolet UV rays from the convex lens 33 side for a predetermined time and the aspherical compound layer is transferred to the convex lens 33. The lens is molded.

According to the above-described method, since the mold 30 is excellent in workability and durability, it is possible to produce a composite lens with high precision relatively cheaply, but the convex lens 33 is difficult to transmit ultraviolet rays depending on the type of optical glass used. As a result, the curing of the ultraviolet curable resin 32 took too much time and the productivity decreased. For this reason, the kind of optical glass used is limited and there exists a problem of inferior design freedom.

In addition, since curing of the ultraviolet curable resin 32 is performed by using ultraviolet UV which irradiated from the convex lens 33 side and transmitted through the lens, ultraviolet UV is easily affected by lens curvature, for example, convex lens. Reference numeral 33 has a function of condensing light, and as shown in Fig. 13, irradiated ultraviolet UV rays are gathered at the center side of the convex lens 33, so that the intensity distribution of ultraviolet rays is nonuniform. Thereby, the unevenness of hardening generate | occur | produced in the ultraviolet curable resin 32, and there existed a problem in manufacture of the composite lens with high precision.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is a composite which enables to manufacture a highly precise composite lens without effecting the type and curvature of the optical glass and to effectively cure the ultraviolet curable resin and without any variation in curing. It aims at obtaining the shaping | molding method of a lens and a composite lens.

In order to achieve the above object, in the molding method of the composite lens according to the present invention, the molding die is molded using a material that transmits light, and the composite layer is irradiated with light from the molding die side, By hardening a photocurable resin so that it may be transferred to a lens.

According to the shaping | molding method of the composite lens mentioned above, since the photocurable resin is hardened by the light beam irradiated from the shaping | molding die side, a photocurable resin can be irradiated with uniform intensity distribution, without a light ray being influenced by lens curvature. Thereby, the photocurable resin does not have the unevenness of hardening, and can manufacture a composite lens with high precision.

In addition, the composite lens according to the present invention allows the lens frame to be integrally formed with the composite layer so that subsequent work steps of assembling the lens frame to the composite lens can be omitted, thereby reducing the number of parts and reducing the cost of the composite lens. can do.

Further objects, features and advantages of the present invention will become more apparent from the preferred embodiments with reference to the accompanying drawings.

1 is an explanatory diagram of a molding method of a composite lens using a convex lens;

2 is a cross-sectional view of the composite lens taken out from the forming die of FIG. 1;

3 is an explanatory diagram of a molding method of a composite lens using a concave lens;

4 is a cross-sectional view of the composite lens taken out from the forming die of FIG. 3;

5 is an explanatory diagram of a method for forming a composite lens consisting of a convex lens for forming an unmolded portion of a composite layer using a light shielding film;

6 is a cross-sectional view of the composite lens taken out from the forming die of FIG. 5;

7 is an explanatory diagram of a method for forming a composite lens consisting of a concave lens for forming an unmolded portion of a composite layer using a light shielding film;

8 is a cross-sectional view of the composite lens taken out from the forming die of FIG.

9 is an explanatory view of a molding method of a composite lens in which a lens holder is integrated in a composite layer;

10 is a cross-sectional view of the composite lens taken out from the forming die of FIG. 9;

Fig. 11 (a) is an explanatory view of a molding method in which the incident surface is made non-planar so that the UV intensity becomes nonuniform in the ultraviolet curable resin, and Fig. 11 (b) shows the composite lens taken out from the molding die in Fig. 11 (a). Cross-section,

12 is a distribution graph of ultraviolet ray intensity,

13 is an explanatory diagram of a conventional molding method for a compound lens.

Various embodiments of the composite lens and the molding method of the composite lens according to the present invention will be described with reference to the drawings.

1 shows a molding method for transferring an aspherical composite layer using a molding die on one surface of a convex lens made of optical glass. The molding die 1 is a material that transmits ultraviolet rays in the range of 200 nm to 400 nm as an example, and is formed of, for example, BK7 (or BSC7). The lower surface of the forming die 1 is formed on a flat surface to become the incident surface 1a of ultraviolet rays.

The above-mentioned shaping die 1 is formed with a concave transfer surface 2 for forming an aspherical composite layer smoothed, and an annular reception surface on which the convex lens described later is mounted on the outer peripheral portion of the transfer surface 2. (2a) is provided. After the predetermined amount of ultraviolet curable resin 3a which becomes the resin material of an aspherical composite layer is dripped on the transfer surface 2, the convex lens 4 which consists of optical glass is set on the shaping | molding die 1, and this convex lens (4) is fixed to the shaping | molding die 1 with the fixing means not shown using the support frame 5. Thereby, the ultraviolet curable resin 3a fills the whole space of the transfer surface 2 and the convex lens 4, and the ultraviolet curable resin overflowed from the transfer surface 2 has the reception surface 2a and the convex lens ( It is further discharged from the gap 7 between the convex lens 4 and the support frame 5 through the bonding surface of 4). The ultraviolet curable resin 3a uses, for example, an acrylic or epoxy-based transparent resin that is cured by ultraviolet rays in the range of 200 nm to 400 nm.

When ultraviolet UV is irradiated on the incident surface 1a of the molding die 1 with the convex lens 4 set on the molding die 1, the ultraviolet UV is parallel to the molding die 1 on the incident surface 1a. By incident, the entire ultraviolet curable resin 3a is irradiated and cured with a uniform intensity distribution. Thereby, the compound lens 8 shown in FIG. 2 by which the aspherical compound layer is formed in the outer peripheral part of the convex lens 4 and the aspherical compound layer 3 which has the unmolded part 3b is shape | molded. By forming this unmolded part 3b, the composite lens 8 can be brought into contact with the lens holder or used for preventing leakage.

3 shows a molding method for transferring an aspherical composite layer using a molding die on one surface of a concave lens made of optical glass. In this case, the concave lens 10 is first set on the support frame 11 so that a predetermined amount of ultraviolet curable resin 12a is dripped onto the concave lens 10. Thereafter, a molding die 14 having a convex-shaped transfer surface 13 from above the concave lens 10 is set and fixed by the support frame 11 and fixing means (not shown).

The molding die 14 is a material that transmits ultraviolet rays in the range of 200 nm to 400 nm similarly to the molding die 1 described above, and is formed of, for example, BK7 or BSC7. The upper surface of the forming die 14 is formed on a flat surface to become the incident surface 14a of ultraviolet rays. As the ultraviolet curable resin 12a, for example, an acrylic or epoxy transparent resin that is cured by ultraviolet rays in a range of 200 nm to 400 nm is used.

By setting the molding die 14 on the concave lens 10, the ultraviolet curable resin 12a fills the entire space of the concave lens 10 and the transfer surface 13 and overflows from the transfer surface 13 to the ultraviolet curable resin. The resin is discharged to the outside through the bonding surface 15 of the concave lens 10 and the support frame 11.

Accordingly, when ultraviolet UV is irradiated from the incident surface 14a of the molding die 14, the ultraviolet UV is incident in parallel into the molding die 14 at the incident surface 14a, whereby the entire ultraviolet curable resin 12a is uniform. Irradiated and cured by intensity distribution. Thereby, the composite lens 16 shown in FIG. 4 by which the aspherical composite layer 12 is transferred to the lens surface of the concave lens 10 is molded.

FIG. 5 is a modified example of FIG. 1, in which a light shielding film 17 such as aluminum foil is mounted on the outer circumferential surface of the transfer surface 2 of the forming die 1, and the unformed portion of the aspherical compound layer is formed on the outer circumferential portion of the convex lens 4. It is a molding method to install. Here, the same reference numerals are given to the same parts as the configuration of FIG. 1.

When ultraviolet UV is irradiated from the incident surface 1a of the molding die 1, ultraviolet UV is incident in parallel into the molding die 1 from the incident surface 1a, and the ultraviolet curable resin 3a is irradiated. At this time, in the part without the light shielding film 17 of the ultraviolet curable resin 3a, it hardens | cures and a composite layer is shape | molded, but the part in which the light shielding film 17 of the ultraviolet curable resin 3a is formed is not irradiated with ultraviolet UV, Become a firebug. Therefore, the composite layer is taken out from the forming die 1, and the uncured portion of the ultraviolet curable resin 3a is removed by, for example, wiping or washing to remove the composite layer, as shown in FIG. The composite lens 18 to which the aspherical composite layer 3 having the unmolded portion 3b of the substrate is transferred is molded. The composite lens 18 can be brought into contact with the lens holder or used for preventing outflow at the portion of the unmolded portion 3b, whereby the assembly accuracy of the composite lens 18 can be improved.

Here, although the light shielding degree of the light shielding film 17 is so preferable that it is high, in order to remove the unhardened part of the ultraviolet curable resin 3a from the convex lens 4 by wiping or washing | cleaning, if the hardening degree of an unhardened part is 5% or less, it will be easy. It is possible. For this reason, the light shielding degree of the light shielding film 17 can be set from the hardening degree of an unhardened part. For example, when the ultraviolet curable resin 3a reaches a curing degree of approximately 50% by irradiation of ultraviolet rays, the light shielding degree of the light shielding film 17 may be 1/10 or less.

FIG. 7 is a molding method in which a light shielding film 19 such as aluminum foil is mounted on the outer circumferential surface of the transfer surface 2 of the molding die 1, and an unmolded portion of an aspherical composite layer is provided on the lens surface of the concave lens 20. FIG. The same parts as in Fig. 5 will be described with the same reference numerals.

In this case as well, the ultraviolet ray is irradiated from the incident surface 1a of the forming die 1 to cure at the portion of the ultraviolet curable resin 3a without the light shielding film 17 to form a composite layer, but the light shielding film 19 is formed. The ultraviolet curable resin 3a in the portion is not irradiated with ultraviolet UV light and becomes an uncured portion, and the outer circumferential portion of the concave lens 20 is removed by wiping or washing and removing the uncured portion of the ultraviolet curable resin 3a. The composite lens 21 to which the aspherical composite layer 3 having the unmolded portion 3b of the composite layer is transferred can be molded.

Fig. 9 is a molding method for simultaneously fabricating a lens frame integrated with an aspherical composite layer. In this case, the molding die 22 also has a flat surface-shaped ultraviolet ray on the lower surface when an ultraviolet-transmissive molding die is used. Has an incident surface 22a.

The molding die 22 is provided with a lens frame molding die 24 so as to be continuous on the outer peripheral side of the concave-shaped transfer surface 23 and the transfer surface 23 for transferring the aspherical composite layer. A predetermined amount of ultraviolet curable resin 3a is dripped at this transfer surface 23. Thereafter, the lens frame 26 having the through-hole 26a made of a resin material assembled together with the convex lens 25 is set while pressing the molding die 22, and the lens frame 26 is set to the molding die 22. By means of fastening means, not shown. Accordingly, the ultraviolet curable resin 3a fills the entire space of the transfer surface 23 and the convex lens 25, and further flows into the lens frame forming die 24 to penetrate through holes 26a of the lens frame 26. In the dome.

Subsequently, as the ultraviolet curable resin 3a is cured by irradiating ultraviolet UV from both the forming die 22 side and the convex lens 25 side, the aspherical composite layer is formed on the convex lens 25 as shown in FIG. 3) is transferred, and the composite lens 28 shown in FIG. 10 in which the lens frame 26 is integrated is formed by the resin 27 that protrudes from the aspherical composite layer 3 and cures. Since the compound lens 28 thus formed can be assembled to the lens barrel using the lens frame 26, the process of setting the lens holder in the compound lens as in the conventional art can be reduced, and the cost can be reduced. have.

11 (a) and 11 (b) are examples of a molding die in which the incidence surface is curved to change the illuminance distribution of ultraviolet rays according to the thickness of the ultraviolet curable resin 3a as an example of the modification of FIG. . In this case, since the ultraviolet curable resin 3a of the transfer surface 2 is made thicker from the center side to the outer circumferential side, as shown in FIG. The incident surface 1b of the convex lens type | mold is formed.

By doing in this way, the ultraviolet-ray UV incident on the incident surface 1b can harden | cure the whole ultraviolet curable resin 3a so that there may be no hardening nonuniformity, and aspheric composite layer 3 with high precision as shown in FIG. The transferred composite lens can be molded.

Here, it is more effective to form an antireflection film having a maximum transmittance with respect to ultraviolet rays in the range of 200 nm to 400 nm on the incident surface of ultraviolet rays in each of the above-mentioned forming dies 1. As the material of the antireflection film, magnesium fluoride (MgF ₂ ) having a refractive index of about 1.38 is used in the case of a single layer film. In the case of magnesium fluoride, the film thickness may be about 54 nm in order to increase the transmittance near the wavelength of 300 nm.

In addition, when the two-layer film is used, hafnium oxide (HfO ₂ ), magnesium fluoride (MgF ₂ ), titanium oxide (TiO ₂ ), magnesium fluoride (MgF ₂ ), tantalum pentoxide (Ta ₂ O ₅ ), and magnesium fluoride (MgF ₂₎ ), Zirconium oxide (ZrO ₂ ) and magnesium fluoride (MgF ₂ ). In addition, these combinations may be substituted with silicon oxide (SiO ₂ ) instead of magnesium fluoride (MgF ₂ ).

As described above, by forming the antireflection film on the incident surface, the intensity of ultraviolet light reaching the ultraviolet curable resin can be improved and the curing time can be shortened as compared with the case where the antireflection film is not formed. do.

Moreover, by using the synthetic resin which hardens the material which forms an aspherical composite layer with an ultraviolet-ray, the resin material and ultraviolet lamp generally marketed widely can be applied, and a composite lens can be manufactured at low cost.

As described above, in the molding method of the composite lens according to the present invention, the molding die is formed by using a material that transmits light, and the composite layer is photocurable by irradiation with light from the molding die side and the light passing through the molding die. Since the resin is transferred to the lens by curing the resin, it is possible to irradiate the photocurable resin with a uniform intensity distribution without being influenced by the lens curvature, thereby making it possible to produce a composite lens with high precision without curing unevenness in the photocurable resin. have.

In addition, since the molding die uses a material that transmits ultraviolet rays of at least 200 nm to 400 nm, the molding die can be manufactured at low cost with a generally inexpensive material that is commercially available.

In addition, by forming a light shielding film on a part of the molding die, an unmolded part can be easily provided in a part of the composite layer, and the lens holder can be assembled with the compound lens to improve the accuracy.

In addition, by forming an antireflection film having a maximum transmittance for light rays in the range of 200 nm to 400 nm on the light incident surface of the molding die, the curing time of the photocurable resin can be shortened and the productivity of the composite lens can be improved. have.

In addition, by making the light incident surface of the molding die into a non-planar shape in which the intensity of light rays irradiated to the photocurable resin becomes a non-uniform distribution, it is possible to form a highly precise composite layer which does not cause curing unevenness even when the photocurable resins have different thicknesses. have.

In addition, since the lens frame is integrally formed with the composite layer, the process of assembling the lens frame to the composite lens can be reduced, and a composite lens having the lens frame can be manufactured at low cost.

In addition, by making the composite layer aspherical, the aberration of the composite lens unit can be improved, and the aberration correction ability when assembled as a unit can be improved.

Moreover, by using the ultraviolet curable resin which a composite layer hardens | cures by the ultraviolet-ray of 200 nm-400 nm, a commercially available material and an ultraviolet lamp can be used, and a composite lens can be manufactured at low cost.

Although the present invention has been described with reference to several embodiments, these are merely illustrative of the present invention and the present invention is not limited to these examples. Those skilled in the art will recognize that various modifications to the present invention are possible, although not specifically disclosed herein, they are also within the spirit and scope of the present invention.

Claims (10)

In the shaping | molding method of the composite lens which transfers the composite layer which consists of photocurable resin hardened | cured by irradiation of a light beam using the molding die on at least one surface of a single lens, The molding die is formed using a material through which light beams pass, and the composite layer is applied to the single lens by irradiating the light beams from the molding die side and curing the photocurable resin by the light beams passing through the molding die. A method for molding a composite lens, characterized in that the transfer. The method of claim 1, And said molding die is a material which transmits light having a wavelength of at least 200 nm to 400 nm. The method of claim 1, Forming a light shielding film on a portion of the molding die so that an unmolded part of the compound layer is formed on the lens surface of the single lens corresponding to the light shielding film. The method of claim 1, An antireflection film having a maximum transmittance with respect to light rays in the range of 200 nm to 400 nm is formed on the light incident surface of the molding die. The method of claim 1, And a non-planar shape in which the intensity of light rays irradiated onto the photocurable resin becomes a non-uniform distribution. The method of claim 1, The compound layer is a molding method of a compound lens, characterized in that the aspherical. The method of claim 1, The composite layer is a molding method of a composite lens, characterized in that the ultraviolet curable resin cured by ultraviolet light in the range of 200nm to 400nm. A composite lens for transferring a composite layer made of a photocurable resin cured by irradiation of light using at least one surface of a single lens by using a molding die, And a lens frame integrally formed with the compound layer. The method of claim 8, The composite layer is characterized in that the aspherical surface. The method of claim 6, The composite layer is a composite lens, characterized in that the ultraviolet curable resin cured by ultraviolet light in the range of 200nm to 400nm.